The Caproni Ca.165 was an Italian

biplane A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, as did many aircraft in the early years of aviation. While ...

fighter developed just before

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, but produced only as a prototype, as the competing Fiat CR.42 ''Falco'' was selected for series production.

Design

Although known for three-engine

heavy bomber Heavy bombers are bomber aircraft capable of delivering the largest payload of air-to-ground weaponry (usually bombs) and longest range (takeoff to landing) of their era. Archetypal heavy bombers have therefore usually been among the large ...

s, Caproni had a long history with fighters, starting in 1914 with an

interceptor Interceptor may refer to: Vehicles * Interceptor aircraft (or simply "interceptor"), a type of point defense fighter aircraft designed specifically to intercept and destroy enemy aircraft * Ford Crown Victoria Police Interceptor, a police car * ...

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

with a single

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, and a

. This was innovative for its time, but it had also no success, as had almost all the fighters proposed in the next decades. Many types of machines were developed by Italian industries prior to World War II, and some were produced at least in limited numbers, but this would not be the case with the Ca.165, a biplane fighter proposed for a fighter contest. In February 1938, it flew for the first time as a prototype. The Ca.165 had a mixed construction. The

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

was framed in steel with a skin of light alloys, while the

wing A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is exp ...

was built out of

wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of ligni ...

with

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skin. Finally, the tail was metallic, also covered in fabric. The Ca.165 had a narrow fuselage featuring an enclosed cockpit. The undercarriage was fixed with spatted wheels. A unique feature of the Ca.165 was the retractable

radiator Radiators are heat exchangers used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars, buildings, and electronics. A radiator is always a ...

, which the pilot could deploy for optimum performance, or retract depending on the flight conditions: completely open in climbs, or closed in level flight and dives. In this way, it was similar to the Morane-Saulnier M.S.406. When deployed, the radiator significantly increased the drag on the aircraft, but increased engine performance and reliability. The engine was a V-12 671 kW (900 hp) Isotta Fraschini L.121 R.C.40 driving a three-bladed

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electric propeller. Top speed was around 465 km/h (289 mph) at 5,350 m (17,550 ft) with a 10,000 m (32,810 ft) ceiling. The range was relatively small, around 672 km (418 mi). Dimensions were 8.1 m (26.6 ft) length, 9.3 m (30.5 ft) height, 2.8 m (9.2 ft) wingspan, 21.4 m² (230.3 ft²) wing surface. The weight was 1,855/2,435 kg (4,090/5,368 lb), with 570 kg ( lb) of payload. After several modifications, the Ca.165 had the tail surface augmented and the aft fuselage lowered to fit a canopy with 360° visibility.

Testing and evaluation

At Guidonia, the aircraft was tested like the many other fighters present for evaluation. However, it was only tested against the Fiat CR.42 ''Falco'', the only other biplane. In mock fights the Ca.165 outperformed the CR.42, thanks to the superior aerodynamics and available power. Despite this, the aircraft was rated inferior as the CR. 42 was more maneuverable and employed a reliable powerplant while the Caproni engine was experimental and had poor reliability. However, the Ca.165 was declared the "winner" of the mock fights, so

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Valle ordered 12 examples on 2 September 1939, although the order was cancelled on 11 October 1939 and changed to 12 Caproni F.5s. This production shift was made even though it involved the payment of a penalty. The Ca.165 was comparable in useful load (570 kg/1,257 lb vs. 575 kg/1,268 lb) and weapons (2 × 12.7 mm/0.5 in, 1 × 7.7 mm/0.303 in) to the CR.42, but it was 200 kg (441 lb) heavier with less wing surface, so it had

wing loading In aerodynamics, wing loading is the total mass of an aircraft or flying animal divided by the area of its wing. The stalling speed of an aircraft in straight, level flight is partly determined by its wing loading. An aircraft or animal with a ...

of 113 kg/m compared to 99 for the CR.42; and that, coupled with the less effective controls, made the Ca.165 less agile. Despite these shortcomings, the Ca. 165's minimum speed was lower (114 km/h/71 mph vs 122 km/h/76 mph), allowing for shorter takeoff runs and slightly better low-speed performance. The Ca.165 had a very slim and small fuselage, but was heavier than the CR.42, which was due, arguably, to the different engine and construction. The Caproni was not really a 'turning fighter', but given the limits of biplanes, was more of an 'energy fighter' with more pronounced capabilities in speed than turning (as was emphasized by the test pilots). An improved version was designed to address the maneuverability limitations, but the development was interrupted. It was built with non-

strategic material Strategic material is any sort of raw material that is important to an individual's or organization's strategic plan and supply chain management. Lack of supply of strategic materials may leave an organization or government vulnerable to disru ...

s (steel and wood mainly), so it could have been at an advantage in the war in terms of strain on the materials industry, but given the type of engine, it is unclear if it was an economically practical aircraft. Caproni tried other ways to improve this powerful biplane, first with the 746 kW (1,000 hp) Piaggio P.XI

radial engine The radial engine is a reciprocating type internal combustion engine configuration in which the cylinders "radiate" outward from a central crankcase like the spokes of a wheel. It resembles a stylized star when viewed from the front, and is ...

, then with a 746 kW (1,000 hp)

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liquid-cooled powerplant, and the redesigned sesquiplane wings as the Ca.173. None of these proposals were successful, at least not enough to pique the interest of the ''

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''. In any case, both engines were far from being sufficiently reliable and were never adopted in large numbers by the

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Cancellation

Perhaps the influence of

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contributed to the selection of the CR.42 ''Falco'' over the Ca.165, although Caproni was an influential company itself at the time. Apparently the bottom line was that the Ca.165's engine was much less reliable and only 44 kW (60 hp) more powerful, while the aircraft itself was 200 kg (440 lb) heavier. The Ca.165, despite being considered the winner in the mock fights, lost the final evaluation. Apparently,

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s flying the Ca.165 managed to outperform the ''Falco'' but disliked the aircraft itself. The faster speed was a more modern concept for a new generation fighter (especially in the interception of fast bombers such as the

Bristol Blenheim The Bristol Blenheim is a British light bomber aircraft designed and built by the Bristol Aeroplane Company (Bristol) which was used extensively in the first two years of the Second World War, with examples still being used as trainers until ...

, which often proved too fast for the ''Falco''), and speed was an increasingly important design consideration in World War II-era aircraft. The engine's poor reliability was also apparent, and when considering which aircraft to produce, this could have been a disadvantage as well. In any case, the Ca.165 was produced in only a single prototype and so vanished from history; instead the Fiat CR.42 became the most produced Italian fighter, despite its overall obsolescence, with almost 1,800 examples built until 1944.

Specifications (Ca.165)

References

External links